"We've been targeting those people where intelligence suggests they are intent on coming to carnival to commit crime and spoil what's a fabulous event for the millions of law abiding people who just want to come and have a good time over the Bank Holiday weekend."

Of those arrested, four were held on suspicion of indecent assault, another five for possession of offensive weapons, and others for various drugs offences, criminal damage and for being drunk and disorderly.

The Notting Hill Carnival is the world's second largest street party, after the Rio Carnival held in Brazil.

The largest crowds are due to arrive on Monday for a parade along the route from Ladbroke Grove to Westbourne Park.

The theme for this year's carnival is the abolition of the slave trade

Ros Bacon, a 54-year-old Londoner said: "I have never been before. I was scared because of the bad publicity but my friend's son is a DJ and he is here, so she convinced me to come.

"It's absolutely wonderful and I'm not worried about security at all. The music is fabulous, I actually quite like hip hop."

Finnish tourist Jukka Myllyniemi said: "I had heard lots of bad stories about it before but I think it's a very positive carnival, with so many people from different cultures.

"The good weather has also made such a difference."

Organisers said this year's theme, "set all free", commemorating 200 years since the abolition of the slave trade has been embraced by carnival goers.